Perhaps you should try some spelling variations:
22quality control » quality control, byquality control, forquality control
_quality control » quality control, byquality control, quality controls
29 reliability » 2 reliability, 9 reliability, 20 reliability
22 safety » 12 safety, 5 safety, 4 safety
2 safety » 5 safety, 4 safety, 3 safety

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: %((22quality control) OR (_quality control))%29 reliability%((22 safety) OR (2 safety)) AND risk%22.
• Adding a wildcard symbol may retrieve word variants: %((22quality control) or (_quality control))%29 reliability%((22 safety) or (2 safety)) and risk%22*.